Groove forming cold rolling tool

ABSTRACT

A ram or mandrel having a splined end to effect a die or drives a cup shaped workpiece into engagement with rollers arranged to press radially against the outer wall of the workpiece and force the workpiece material into the valleys between splines thus forming a complementary splined formation of the cup. A plurality of forming rollers are operative as a male die. Each roller is backed by a pair of supporting rollers wherein a forming roller and a pair of backing rollers form a unit radially adjustable relative the workpiece, each such unit being carried in a relatively stationary sector shaped body, all units being surrounded by a common reinforcing radial support ring and carried on a bed plate, there being one such unit for each formation, such as a crevice, to be formed in the workpiece.

United States Patent 1191 1111 3,729,970 Propach et al. 1 51 May 1, 1973 1 1 GROOVE FORMING COL-D ROLLING 1,047,167 12 1912 Carlson ..72/213 TOOL 1,605,828 11/1926 Frahm 569,431 10/1896 Ser eant.... [75] Inventors: Otto Propach, Markdorf; Heinz 473019 4/1392 p g Veittinger, Langenargen; Karl 2,568,730 9/1951 Guthmannm. Jauch, Ravensburg, all of Germany 3,457,759 7/1969 Doerr et al. [73] Assignee: Z ahnradfabri? Friedrichshafen Ak- Primary Examiner Lowen A. Larson g fif zg f Fnednchshafen Attorney-Zalkind, Home & Shuster [22] Filed: Apr. 9, 1971 [5 ABSTRACT [21 A l N 132,854 A ram or mandrel having a splined end to effect a die or drives a cup shaped workpiece into engagement with rollers arranged to press radially against the outer 0 F [3 1 orelgn Apphcatmn Pnorlty Data wall of the workpiece and force the workpiece materi- Apr. 14, 1970 Germany ..1 20 17 709.7 81 into the valleys between plines thus forming a com plementary splined formation of the cup. A plurality 52 us. c1. ..72/208 72/212 72/178 of rollers are Operative as a male Each [51 Im. c1. ..B2lb 17/06 B211 31/30 wile is baked by a Pair Ofsuppmting rollers wherein [58] Field of Search 5 178 212 a forming roller and a pair of backing rollers form a 3 unit radially adjustable relative the workpiece, each such unit being carried in a relatively stationary sector shaped body, all units being surrounded by a common [56} References cued reinforcing radial support ring and carried on a bed UNITED STATES PATENTS plate, there being one such unit for each formation,

such as a crevice, to be formed in the workpiece. 98,807 1/1870 Sellers ..72/242 3,143,010 8/1964 Saxl 72/242 9 Claims, 3 Drawing Figures Patented May 1 1973 2 Sheets-Sheet 1 F I9. I

INVENTORS I 0H0 Propoch Heinz VeitI/hger Karl Jouch 2 Sheets-Shoot 2 Fig. 2

Q 73 H A X I8 I38 INVENTORS .Ottp Propach Heinz Veitfinger Karl Jauch ATTORNEY 1 GROOVE FORMING COLD ROLLING TOOL Briefly, the invention comprises a radial array of grooving rollers each. carried in a radially adjustable body or unit wherein said rollers are all in planes containing a workpiece axis so that a cylindrical workpiece can be forced past peripherally ridged working surfaces of the grooving rollers. The workpiece is fitted over a longitudinally ribbed die having valleys complemental to the contour of the surface of the rollers and radial adjustments of the units are made so that as the workpiece is driven, as by a ram, the lower end of which may also have the die integral therewith, the grooving or forming rollers cold roll respective grooves longitudinally in the workpiece.

A particular feature of the invention resides in the fact that the units, each comprise a pair of backup or support rollers which engage the respective forming roller at rear portions to buttress it against working stress. The support rollers are preferably of complemental contour relative to the contour of the respective forming roller and are so disposedas to engage the respective forming rollers on each side of the line of force which the, forming roller must exert against the workpiece in order to effect the operation, the reaction support beingequally divided between the support rollers.

By such construction, certain drawbacks of prior art mechanisms of this kind are overcome since smaller forming rollers can be used without requiring very heavy and large support bodyconstruction. Namely, the larger the roller. the greater theforce it exerts and the larger and heavier. the support body would have to be. However, by the use of support rollers the thrust force on the forming roller can be absorbed by the supporting rollers and a saving in overall construction is made.

Further, the mounting per se of each form roller is simplified and smaller and, in order to exert the same amount of actual forming force, forming rollers used in the combination of the invention can be made smaller. Arrangements of supporting rollers are not new per se. Certain types of rolling mills for producing tapering discs and arrangements for cold rolling grooves or tooth profiles with a plurality of forming rollers arrayed in a circle around a workpiece. have likewise been heretofore known. However, in these instances the forming rollers actuallymove bodily and do not merely rotate. In the present invention, the forming rollers merely rotate and there is no necessity for the complexity of supports and mounts to provide for a travelling motion in the course ofan operation.

A further and very important feature is the fact that the construction of the present invention. can be used on conventional presses.

Two modifications of the invention are disclosed herein wherein the stresses in the workpiece are tensile in one instance and compressive in another.

A detailed description of the invention now follows in conjunction with the appended drawing in which FIG. 1 is a cross section through l-l of FIG. 2;

FIG. 2 is a fragmentary section through Il--ll of FIG. 1, and

FIG. 3 is a fragmentary longitudinalsection through a modified portion of the invention.

In essence, the invention comprises a base 1 which carries a circularly arrayed plurality of generally sector-shaped bodies 4 each of which is comprised in a radially adjustable unit carrying a respective forming roller 6 backed up by force supporting rollers 7 and 7A. Each such unit is radially adjustable so as to predetermine the position of the respective roller 6 with respect to a workpiece W which in FIG. 1 is seen to be a metal cup held by a magnet 51 when fitted at the lower end of a ram 9. The integral lower end of the ram 9 is longitu dinally fluted at 9A to form a female die, and the upper end is secured to a pressure pad 2 by screws 35. Die valleys are shown at 21.

The axis of the ram is the axis of the circle about whichrthe various units radiate and is in the medial plane of each of the rollers 6. Thus, if it be assumed that the workpiece W is elevated somewhat about the position shown in FIG. 1, the initial position prior to forming, and ram 9 then forced downwardly as by a force exerted on the pressure pad 2, it will be apparent that with proper radial position of the peripheries of rollers 6 having ridges which fit the contours of valleys 21 between flutes of the ram die, the cylindrical wall of the cup will be longitudinally corrugated or splined, or formed with teeth or grooves, 21, depending upon the profile of the peripheries of male die rollers 6 and die 9A, for any desired shape.

The rollers 6 are, of course, forced to rotate while the work is being forced past them but they do not travel bodily.The line of thrust force or reaction force which must be supported is indicated by the line P on FIG. 1 and the disposition of the supporting rollers 7 and 7A is such that a linejoining their axes is normal to the line P. This effects engagement of the reinforcing rollers at such points on the respective rollers 6 as to provide maximum supporting effect while the workpiece is driven past the rollers 6 and. divides the backup stress equally between rollers 7 and 7A. Upon completion of the rolling operation an ejector pin 10 may be utilized to push the formed cup off the ram.

Referring now to the details of construction of a unit of the mechanism, each body 4 is radially adjustable by a wedge 5 which can be moved vertically as by a pair of screws 13. The wedge 5 in each instance is intermediate to body 4 and the inner circle surface 3A of a rigid housingring 3. Ring 3 is secured to base 1 as by screws 38.

For slidable guidance each of the units has a plate 8 secured as by screws indicated by reference characters 39 to the top of ring 3 and the undersurface of each said plate is provided with radial guide slots for tongues 25 and 26 which will be understood to be fastened by screws 40 in shallow radial slots as shown in ring 3 and body 4, respectively, while protruding into a slot in plate 8. Similarly, slide guide means such as tongues 27 and 28 are secured to base 1 by screws such as 40 and protrude into a radial guide slot at the bottom of body 4. Actually, tongue 25 provides initial radial alinement for plate 8 and does not engage body 4 for moving guidance.

Anchor screws 11 pass through vertical side slots in adjoining bodies 4 for threaded connection with base 1. Thus each anchor screw abuts a ledge at its head end, as seen in FIG. 1, in each of the adjoining support bodies 4 to clamp the bodies to base 1.. Additional anchor screws 12 pass through slots in each body 4 and thread into the base.

For radial adjustment of a unit it is only necessary to loosen the anchor screws and the screw 18 which is threaded in plate 8 and abuts the top side of wedge Thereafter, screws 13 can be rotated to raise or lower wedge 5 in the tapering channel afforded between body 4 and ring surface 3A as seen in FIG. 1. If the wedge be lowered there is, of course, no driving force on body 4 in which case the units can be pulled manually rearwardly away from the workpiece W and then set accurately towards the workpiece by the drive force of the wedge 5 in rising motion. The screw 18 holds the wedge against moving upwardly. Thereafter, the anchor bolts can be tightened.

The radial adjustment per se of a forming roller 6 is effected by mounting it on a pin 22 carried in slidable journal blocks 19 and 20 carried in slots in parallel spaced cheeks of body 4. Roller 6 rotates on needle bearing pins 47 and is secured within slide block 19 as by a set screw 46. The slide blocks are slidable in the respective slots which have respective support surfaces 29 and 30. An end gap 31 between the blocks and the slot ends is indicated by the broken line in FIG. 1. The surfaces 29 and 30 have the same slant as that of the force line P. A wedge block 23 for slide block 19 is provided and a wedge block 24 for slide block 20 is provided, in the respective slots, each being movable by a screw 44 threaded in a respective notch in the body 4 so as to adjust forming roller 6 toward the support rollers 7 and 7A, in order to effect proper reinforcing engagement. This is particularly useful to compensate for wear. It will be noted that the symmetrical arrangement provides for all reaction forces to be supported by the support rollers and that actually the pin 22 carries no heavy load. Theoretically the pin 22 carries no load at all in the direction of the line P which is the main force line for the direction of force exerted by the forming roller, and all radial engaging adjustment is made in the direction of that line.

The support roller 7 is preferably carried on needle bearing pins 48 secured by washers 49 within bushings l4 and carried in the body 4. The same type of construction utilizes bushings 16 and 17 for roller 7A. All bushings may be secured as by screws 41 in body 4.

From the preceding description it will be apparent that the mechanism has one forming unit for each valley 21 to be formed, although, it will be understood that different working complemental surfaces of male and female design are usable. Further, it will be apparent that there is a structural coaction between adjoining units in that anchor screws 11 are common to two units and therefore all units are to be positioned and secured by screws 12 before final tightening of screws I]. This effects a complete ring-like structure of the units having interdependent lateral sccur'cment.

Referring to FIG. 3, the modification comprises a ram 60 having the lower end 61 which terminates in a flat bottom 62 against the workpiece W of cup shape placed on a die head 64 on the upper end of a mandrel 63 and which die head has longitudinal fluting affording forming valleys 21. Thus, when ram 60 moves downwardly, the workpiece is forced through the rollers (indicated by phantom lines) for cold rolling longitudinal flutes or splines, etc.

The ejection of the formed piece can be effected by member 66 actuated hydraulically as by piston 65.

In the modification of FIG. 3, the longitudinal stresses in the wall of the workpiece are compressive as compared with tensile stresses in the wall of the workpiece shown in FIG. 1.

We claim:

1. An apparatus for cold rolling longitudinal grooves in a cylindrical workpiece comprising a base having a plurality of sector shaped radially arrayed roller support bodies carried thereon, each said body having a forming roller extending therefrom and being thus radially arrayed with respect to the axis of said workpiece for engagement therewith; each said support body having a pair of support rollers for the respective forming roller and in engagement therewith to absorb the force occasioned by a rolling operation; a cylindrical die means disposed to reciprocate on said axis and having respective contour grooves complimental to respective forming rollers and having a diameter to slidably receive said workpiece; and ram means for driving said die means to effect engagement of said workpiece with said forming rollers; a housing ring secured to said base and encompassing the outer ends of said roller support bodies for absorbing radial thrust force therefrom effected during a rolling operation.

2. An apparatus as set forth in claim 1, respective adjusting means comprising a wedge intermediate each said support body and said housing ring through which radial thrust force is transmitted from said support bodies to said ring, and means for actuating said wedges to effect radial adjustment of said support bodies with respect to said axis.

3. An apparatus as set forth in claim 2, including roller adjusting means in each said support body for radial adjustment of the respective forming roller relative to the respective support rollers.

4. An apparatus as set forth in claim 1, respective adjusting means comprising a wedge intermediate each said support body and said housing ring through which radial thrust force is transmitted from said support bodies to said ring, and means for actuating said wedges to effect radial adjustment of said support bodies with respect to said axis, said means for actuating said wedges comprising a plate surmounting said support bodies and said housing ring and a respective screw extending through said plate and threadedly engaging respective wedges for actuation thereof.

5. An apparatus as set forth in claim 1, including roller adjusting means in each said support body for radial adjustment of the respective forming roller relative to the respective support rollers, each said roller adjusting means comprising pins supporting respective forming rollers and a slidable support block for each end of each pin carried in the respective support body, and a respective wedge abutting each said support block and carried in the respective support body and movable to move said support blocks to adjusted positions, including respective slots in which said support blocks are slidable at the angle of the direction of thrust force of the respective forming roller.

6. An apparatus for cold rolling longitudinal grooves in a cylindrical workpiece comprising a base having a plurality of radially arrayed roller support bodies carried thereon, each said body having a forming roller ex tending therefrom and being thus radially arrayed with respect to the axis of said workpiece for engagement therewith; each said support body having a pair of support rollers for the respective forming roller and in engagement therewith to absorb the force occasioned by a rolling operation; a cylindrical die means disposed to reciprocate on said axis and having respective contour grooves complimental to respective forming rollers and having a diameter to slidably receive said workpiece; and ram means for driving said die means to effect en gagement of said workpiece with said forming rollers; 21 housing ring secured to said base and encompassing the outer ends of said roller support bodies for absorbing radial thrust force therefrom effected during a rolling operation, respective adjusting means comprising a wedge intermediate each said support body and said housing ring through which radial thrust force is transmitted from said support bodies to said ring, and means for actuating said wedges to effect radial adjustment of said support bodies with respect to said axis.

7. An apparatus as set forth in claim 6, including respective adjusting means comprising a wedge intermediate each said support body and said housing ring through which radial thrust force is transmitted from said support bodies to said ring, and means for actuating said wedges to effect radial adjustment of said support bodies with respect to said axis, said means for actuating said wedges comprising a plate surmounting said support bodies and said housing ring and a respective screw extending through said plate and threadedly engaging respective wedges for actuation thereof.

8. An apparatus as set forth in claim 6, including roller adjusting means in each said support body for radial adjustment of the respective forming roller relative to the respective support rollers.

9. An apparatus as set forth in claim 6, including roller adjusting means in each support body for radial adjustment of the respective forming roller relative to the respective support rollers, respective adjusting means comprising a wedge intermediate each said support body and said housing ring through which radial thrust force is transmitted from said support bodies to said ring, and means for actuating said wedges to effect radial adjustment of said support bodies with respect to said axis, said means for actuating said wedges comprising a plate surmounting said support bodies and said housing ring and a respective screw extending through said plate threadedly engaging respective wedges for actuation thereof. 

1. An apparatus for cold rolling longitudinal grooves in a cylindrical workpiece comprising a base having a plurality of sector shaped radially arrayed roller support bodies carried thereon, each said body having a forming roller extending therefrom and being thus radially arrayed with respect to the axis of said workpiece for engagement therewith; each said support body having a pair of support rollers for the respective forming roller and in engagement therewith to absorb the force occasioned by a rolling operation; a cylindrical die means disposed to reciprocate on said axis and having respective contour grooves complimental to respective forming rollers and having a diameter to slidably receive said workpiece; and ram means for driving said die means to effect engagement of said workpiece with said forming rollers; a housing ring secured to said base and encompassing the outer ends of said roller support bodies for absorbing radial thrust force therefrom effected during a rolling operation.
 2. An apparatus as set forth in claim 1, respective adjusting means comprising a wedge intermediate each said support body and said housing ring through which radial thrust force is transmitted from said support bodies to said ring, and means for actuating said wedges to effect radial adjustment of said support bodies with respect to said axis.
 3. An apparatus as set forth in claim 2, including roller adjusting means in each said support body for radial adjustment of the respective forming roller relative to the respective support rollers.
 4. An apparatus as set forth in claim 1, respective adjusting means comprising a wedge intermediate each said support body and said housing ring through which radial thrust force is transmitted from said support bodies to said ring, and means for actuating said wedges to effect radial adjustment of said support bodies with respect to said axis, said means for actuating said wedges comprising a plate surmounting said support bodies and said housing ring and a respective screw extending through said plate and threadedly engaging respective wedges for actuation thereof.
 5. An apparatus as set forth in claim 1, including roller adjusting means in each said support body for radial adjustment of the respective forming roller relative to the respective support rollers, each said roller adjusting means comprising pins supporting respective forming rollers and a slidable support block for each end of each pin carried in the respective support body, and a respective wedge abutting each said support block and carried in the respective support body and movable to move said support blocks to adjusted positions, including respective slots in which said support blocks are slidable at the angle of the direction of thrust force of the respective forming roller.
 6. An apparatus for cold rolling longitudinal grooves in a cylindrical workpiece comprising a base having a plurality of radially arrayed roller support bodies carried thereon, each said body having a forming roller extending therefrom and being thus radially arrayed with respect to the axis of said workpiece for engagement therewith; each said support body having a pair of support rollers for the respective forming roller and in engagement therewith to absorb the force occasioned by a rolling operation; a cylindrical die means disposed to reciprocate on said axis and having respective contour grooves complimental to respective forming rollers and having a diameter to slidably receive said workpiece; and ram means for driving said die means to effect engagement of said workpiece with said forming rollers; a housing ring secured to said base and encompassing the outer ends of said roller support bodies for absorbing radial thrust force therefrom effected during a rolling operation, respective adjusting means comprising a wedge intermediate each said support body and said housing ring through which radial thrust force is transmitted from said support bodies to said ring, and means for actuating said wedges to effect radiaL adjustment of said support bodies with respect to said axis.
 7. An apparatus as set forth in claim 6, including respective adjusting means comprising a wedge intermediate each said support body and said housing ring through which radial thrust force is transmitted from said support bodies to said ring, and means for actuating said wedges to effect radial adjustment of said support bodies with respect to said axis, said means for actuating said wedges comprising a plate surmounting said support bodies and said housing ring and a respective screw extending through said plate and threadedly engaging respective wedges for actuation thereof.
 8. An apparatus as set forth in claim 6, including roller adjusting means in each said support body for radial adjustment of the respective forming roller relative to the respective support rollers.
 9. An apparatus as set forth in claim 6, including roller adjusting means in each support body for radial adjustment of the respective forming roller relative to the respective support rollers, respective adjusting means comprising a wedge intermediate each said support body and said housing ring through which radial thrust force is transmitted from said support bodies to said ring, and means for actuating said wedges to effect radial adjustment of said support bodies with respect to said axis, said means for actuating said wedges comprising a plate surmounting said support bodies and said housing ring and a respective screw extending through said plate threadedly engaging respective wedges for actuation thereof. 